The invention relates to an axial bearing comprising two runner plates, between which rolling elements roll on associated raceways. The two runner plates are held together by a sleeve having legs running radially and axially to form a captive structural unit. At least one of the runner plates is encompassed around its circumferential surface by the leg running axially.
An axial bearing of such a generic design is known from DE 44 09 734 A1. It comprises two runner plates which are combined by means of a sleeve engaging over their radial circumferential surface to form a bearing unit. The sleeve has a leg which runs axially and engages around both runner plates at their circumferential surfaces. The leg running radially is formed by means of a flanging operation.
It has the disadvantage is that the flanging operation is a complicated additional operation which makes the outlay on production of the entire structural unit more expensive. Added to this is the fact that, in the event of faulty installation, the runner plates also suffer, so that the complete structural bearing unit can no longer be used. Furthermore, the fact that such a bearing has to be destroyed in the event of necessary disassembly has a detrimental effect.
It is therefore an object of the invention to provide a generic structural axial bearing unit which does not have the disadvantages listed above.
According to the invention, the sleeve is formed as a resilient retaining ring having two settings. The ring is placed above one of the runner plates, here called the upper plate. The sleeve has a plurality of holding tongues which are spaced apart uniformly from one another in the circumferential direction around the ring and which run axially. The tongues have free ends from which holding lugs originate and the lugs are angled over radially and engage behind the other runner plate called the lower plate. A circumcircle of the holding lugs, in their state not connected behind the lower runner plate, have a first diameter D1 greater than the diameter of the runner plates and, in the state of the lugs connected behind the runner plate, the lugs have a second diameter D2 that is smaller than the diameter of the runner plates. The diameter D2 of the circumcircle is set by applying a force to the retaining ring by changing the position of its radial legs, wherein the legs runs with respect to a bearing axis at an angle xcex1 of less than 90xc2x0 at the first diameter D1, and the legs run at an angle of 90xc2x0 at the second diameter D2 of the circumcircle.
Such an axial bearing unit, comprising a plurality of components, may accordingly be installed quickly and simply. Another substantial advantage is that, when the procedure is reversed, simple and, above all, nondestructive disassembly of the structural bearing unit is also possible.
The holding lugs may engage behind a flat on the lower runner plate. This ensures that the axial bearing structural unit will hold together reliably.
The two runner plates may have the same radial extent and the holding tongues may encompass the runner plates at and around their circumferential surfaces. According to a further feature, one runner plate, such as the lower plate, has an axial ledge on its outer peripheral circumferential surface which encloses the other runner plate at its circumferential surface.
In an additional embodiment, the runner plate away from the ring has an axial ledge on its inner peripheral circumferential surface, which is connected to or is part of an outer ring of a radial bearing. This provides a combined radial-axial structural bearing unit in a simple way.
Other objects and features of the invention are explained using the following exemplary embodiments.